That sample proved he was four billion times more likely to be the same person who left material under her fingernails, than any other person.
He was sentenced on April 6, 2004, to a minimum non-parole period of 10 years.
Last week the 40-year-old appeared before a three-member New Zealand Parole Board which, in a three page decision released yesterday, declined his parole.
"Looking at the material overall, there is no question in our mind that Mr Mangles poses an undue risk to the safety of the community," the board concluded.
"Parole must be declined."
It was Mangles first consideration of parole on his life sentence for murder.
He had a low prison security classification at an undisclosed New Zealand prison.
The board noted Mangles had been consistent in claiming to have no memory of the murder, and sentencing notes indicated he was probably under the influence of alcohol and possibly drugs.
The board noted "the profound suffering caused to members of the deceased's family who are, of course, victims themselves".
A January psychological assessment report assessed Mangles risk as high, and he was noted as being "ambivalent" about participation in programmes, such as the Special Treatment Unit Rehabilitation Programme.
That programmes provides treatment to serious violent offenders with a high risk of re-offending.
Mangles told the Parole Board he was motivated to attend such programmes.
It was recommended he be placed on the programme at the earliest possible time.
"Whatever way we look at things, however, there is a long way to go for Mr Mangles not only in terms of rehabilitation but also reintegration which will have to proceed on a very gradual and cautious basis," the board noted.
Mangles told the board he did not see parole being a realistic possibility "within the next several years".
The board was of the view Mangles should be next seen by an Extended Board for a postponement order, which is given to an offender deemed not suitable for release at the time when they were next due to be considered for parole.
That Extended Board, which may see Mangles at the May hearings, may consider calling for a neuropsychological assessment.
A psychological report and parole assessment of Mangles noted his memory loss, believed to have been sustained in a severe beating by the Road Knights gang in 1999.
Mangles was in a coma for several days following the assault and required reconstructive surgery to his head, other parts of the his body, and he lost an eye.
That psychological report raised the question "whether Mr Mangles is really unable to remember the detail of the offending or whether he is simply avoiding the issues".
"He tells us that he is struggling to comprehend what was going on in his life back then", the board noted.
